The August 08, 2012, 06:23 UTC, Mw 4.5, Yorba Linda, California
Earthquake data recorded by the USGS National Strong-Motion Network (NSMN) are available
via the NSMP ftp server in the folder (directory) "20120808_0623" (ftp://smftp.wr.usgs.gov/20120808_0623).
The time series provided are available in uncorrected acceleration, corrected
acceleration, corrected velocity, corrected displacement, response spectra (relative
displacement, relative velocity, pseudo-velocity, and absolute acceleration), and Fourier
amplitude spectra of corrected acceleration. All of the data are in SMC format. Data
from other sources are available at the Center for Engineering Strong-Motion
Data (CESMD).

In a departure from previous file-naming conventions (where
for a particular channel the different the time series data all had the same filename, and
thus required separate directories for each data type), the file names for the data have
the following form:

uncorrected
acceleration:

RRRRc_u.smc

corrected acceleration:

RRRRc_a.smc

corrected velocity:

RRRRc_v.smc

corrected displacement

RRRRc_d.smc

response spectra:

RRRRc_r.rs2

Fourier amplitude spectra (f):

RRRRc_f.fs1

where 'RRRR' is the four-digit recorder serial number
(including leading 0's) for the USGS data, 'c' is the channel number of the recorder ('a'
corresponds to channel 1, 'b' to channel 2 , etc), the '_x' is used to
identify the data type, and the suffix refers to the data format (rs2 and fs1 are valid
SMC format types recognized by the BAP
processing program.

The data are stored in two directories: uncorrected (only
uncorrected acceleration) and corrected (all of the corrected and processed data,
including acceleration, velocity, displacement, response spectra and Fourier amplitude
spectra. This convention for organizing the data was implemented to avoid confusion
between the directory names (Vol1, Vol2, Vol6) previously used for some earlier
events and the standard conventions for Volume1, Volume2 and Volume 3 processing.

Information on how the data are processed can be found in the
section on DATA PROCESSING.
Note that these data were processed using an acausal Butterworth locut filter.

To facilitate downloading the data, the data have been compressed
into PC compatible ".zip" format. The same zip file is located in the
"zips" folder in "20120808_0623/" on the NSMP ftp server, "ftp://smftp.wr.usgs.gov/20120808_0623".